Rockbox

https://git.rockbox.org/cgit/rockbox.git/commit/?id=77f8c9c9f12f1a520467868047574fe0af7a1556

Is that commit not the same one I have already linked in my issue? In any case it doesn't work correctly/reliably in my testing.

yes the link you posted above links into wikipedia instead of gerrit

Fixed. Worked for me when I tested it before posting, odd.

Can you post a link that identifies the specific remote you're using?

The official Apple Radio Remote. This one.

Cool, thanks. I found one for really cheap, and it should get here by the weekend.

Ok, I have the radio remote, and it seems to generally work as I'd expect (on a mini2g and nano2g), with the glaring exception that the actual _radio_ doesn't produce any audio – however it does tune properly, and reports DAB station information. And the audio quality out of the headphones was pretty crappy.

Then I booted into the apple firmware… and okay, this remote is clearly defective. Lovely.

The commit also does say that it only adds radio support on the 5g, and other iPods will only have remote function. I suspect on iPods other than the 5g, the remote function works better as a result. Will test on my nano 1g soon.

Maybe not. First try testing on a fresh install on the nano 1g, hit play/pause once, got

Data abort at 00070000 (0)
pc:00070000 sp:000c43d8
     A: 40005cc8
     A: 40005cc8
bt end

Remote briefly worked on second boot, then I tested the FM Radio option.
FM Radio option displays in menu, but does not produce output.
After exiting the FM Radio menu and returning to normal music playback, the buttons failed to work, and it crashed again after a few button presses.

Data abort at 0007ee3c (0)
pc:0007ee3c sp:000c43d8
     A:00023e64
bt end

Coming back to this issue now the the Dev Builds have fixed flash issues, this commit is the only thing keeping me from using them. Can we just get this reverted? It causes instability, breaks the function of the remote, and (at least in my case) doesn't actually enable the FM Radio.

Unless there was an earlier commit I'm missing that broke the remote in some way, and this was an attempt to fix it. In that case, we need a fix that's actually a fix.

I've just tried the latest dev build (d1a92aafff-210628) on my 5.5G
Tried both powering up with remote and headphones fitted as well as powering up and fitting remote and headphones after boot.
The remote, when playing music, adjusted volume up/down as well as previous/next track and paused.
When on Radio, adjusted volume up/down as well as previous/next station and muted.
While not as smooth as the Apple firmware it did appear to function in the same manner.

If I get time I'll revisit this and see if I can see the reported issue.

Please note that the radio only works on the 5/5.5G at the moment although the remote functionality should work when playing music on most ipods.

Trying the latest build, the instability I faced before seemed to be gone at first, and everything worked fine. The FM Radio option was showing properly in the menu, and the playback controls worked consistently (more on volume later). However, when I decided to test the Radio functionality, the menu option was not there. I rebooted and disconnected and reconnected few times to try and get it to appear, and the controls stopped working as well. I had to connect it to USB and then disconnect it, and it worked again. Testing the radio, still nothing. No signal on any station, just some white noise. Radio still works fine on OFW, so it isn't my unit. Overall, the only improvement from previous testing seems to be that I haven't seen a crash from using the controls.

On the subject of volume control, even if everything worked as intended, having the radio remote's volume buttons control rockbox's volume is pointless. The radio remote's volume buttons should only control the remote's own internal amplification. Its changes to rockbox's volume don't even take affect until you trigger a normal volume change using the clickwheel (which you can test by plugging into the normal headphone jack and adjusting volume with the remote), and they also can bypass your set maximum volume (which is not okay). They also don't trigger the 'changing volume' event for themes ('%mv' if i remember correctly) so you can't see the volume change on some themes. Even if it worked perfectly, the volume buttons controlling both Rockbox's volume and the remote's own volume would lead to very confusing behavior.

As it stands, as a remote it's usable, but very far from ideal, and as a radio, it still doesn't work at all for me (which I'm not too worried about personally).